1. Technical Field
The present invention relates to a display device and a driving method thereof. More particularly, the present invention relates to a driving method that reduces power consumption and that prevents deterioration of visibility in a display device, and a display device employing the driving method.
2. Discussion of the Related Art
Computer monitors, televisions, mobile phones, and the like are or include display devices. Example display device types include a cathode ray tube display, a liquid crystal display, and a plasma display.
The display device may include a graphics processing unit (GPU), a display panel, and a signal controller. The GPU transmits image data to be displayed by the display panel to the signal controller, and the signal controller generates a control signal to drive the display panel and transmits the control signal along with the image data to the display panel, thereby driving the display device to display an image.
The image displayed by the display panel is generally divided into a still image and a moving image. A still image is displayed when the display panel displays several frames per second, and the image data of each frame is the same, for example. A moving image is displayed when the display panel displays several frames per second, and the image data of each frame are different from each other, for example.
In the still image case, the signal controller receives the same image data from the GPU for every frame the still image is displayed, thereby increasing power consumption of the display device.
To reduce the power consumption of the display device, a frame memory has been added to the signal controller to store the image data of the still image, and the stored image data is provided to the display panel while the still image is displayed. This is referred to as a pixel self refresh (PSR) technique. In the PSR technique, the image data is not transmitted from the GPU while the still image is displayed such that the GPU is not activated, thereby reducing the power consumption.
However, when the display device is driven with the PSR technique, the frame memory is added such that the power consumption is increased. Accordingly, there exists a need to reduce power consumed by a display device.